Direct Catalytic Desaturation of Lactams Enabled by Soft Enolization
作者:Ming Chen、Guangbin Dong
DOI:10.1021/jacs.7b04722
日期:2017.6.14
N-protected lactams to their conjugatedunsaturated counterparts under mildly acidic conditions. The reaction is consistently operated at room temperature and tolerates a wide range of functional groups, showing reactivity complementary to that of prior desaturation methods. Lactams with various ring sizes and substituents at different positions all reacted smoothly. The synthetic utility of this method
For the construction of the tricyclic core of manzamine A (1), the Diels-Alder reactions of some dihydropyridinones were surveyed. The N-protecting group of the dihydropyridinone played an important role in achieving a successful Diels-Alder reaction. In view of its electron-withdrawing character as well as its thermal stability, the p-toluenesulfonyl protecting group was found to be best in our synthesis. An effective method for the preparation of 3-alkyldihydropyridinones via the Michael addition to dehydroalanine derivatives has also been devised. By the utilization of a high-pressure Diels-Alder reaction of the N-tosyl-3-alkyldihydropyridinone (17) with the Danishefsky diene, a facile construction of the central pyrroloisoquinoline skeleton (21) was successfully achieved.
NAKAGAWA, MASAKO;LAI, ZIPING;TORISAWA, YASUHIRO;HINO, TOHRU, HETEROCYCLES, 31,(1990) N, C. 993-1002
As a continuation of our efforts directed towards the development of anti-diabetic agents from natural sources, piplartine was isolated from Piper chaba, and was found to inhibit recombinant human ALR2 with an IC50 of 160 μM. To improve the efficacy, a series of analogues have been synthesized by modification of the styryl/aromatic and heterocyclic ring functionalities of this natural product lead